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3
votes
1answer
662 views

How to compute the 2D equations of 3D circular arcs?

I'd like to obtain these equations for the ellipses produced by the perspective projections of (3-dimensionally transformed) circles. This is useful for rendering in 2D contexts which provide curve ...
3
votes
0answers
83 views

Filling Closed Shapes

Game Engine : Unity 5.1 Developing on Windows 7 Hello, I am using Vectrosity to draw some some shapes on screen run time. I also need to fill these shapes and none of them are really trivial shapes. ...
2
votes
2answers
4k views

What is the difference between an orthographic and oblique projection?

They both seem to be a parallel projection. I know that the angles of axes of viewing differ based on the type of orthographic projection (eg, an isometric projection has equal angles for all the axes)...
2
votes
2answers
214 views

How do I convert screen coordinates to between -1 and 1?

I'm writing a function that allows me to click on my tiles. The origin for my tiles is the center, however, the mouse's origin is the top left. I need a way to transform my mouse coordinates into my ...
2
votes
2answers
263 views

What kind of projection is used here?

Tibia is a 2d game, but it's sprites are drawn using certain kind of orthographic projection that is not the same I'm used to: I'm trying to figure out what projection is used here. I've guessed ...
2
votes
2answers
2k views

How should I calculate world and projection matrices in this scenario?

I'm trying to understand transformation matrices. Suppose I use the camera from this StackOverflow answer, this is how my view matrix would look: Matrix.Identity * Matrix.CreateTranslation(-Position....
2
votes
3answers
1k views

Game Engine which can provide 360 degree projection for PC [closed]

I'm searching Game engine which can provide 360 degree real-time projection. I've already achieved this by using VBS2 Game Engine. (Ref.: http://products.bisimulations.com/products/vbs2/vbs2-multi-...
2
votes
1answer
2k views

How do I check why is no output on screen?

I'm using OpenGL 3.3+, and I'm trying to create an orthographic projection to draw on screen. I have the model data in a buffer: X Y 0, 0 50, 100 100, 0 And I create my Model-View-Projection ...
2
votes
1answer
188 views

Is it bad-practice using left-handed coordinate system in OpenGL eye-space?

In the engine I am currently programming I want to use a left-handed coordinate system for eye-space instead of the glFrustum standard right-handed one. Is that in anyway considered bad practice?
2
votes
1answer
952 views

How to do geometric projection shadows?

I have decided that since my game world is mostly flat I don't need better shadows than geometric projections - at least for now. The only problem is I don't even know how to do those properly - that ...
2
votes
1answer
816 views

How to create projection/view matrix for hole in the monitor effect

Lets say I have my XNA app window that is sized at 640 x 480 pixels. Now lets say I have a cube model with its poly's facing in to make a room. This cube is sized 640 units wide by 480 units high by ...
2
votes
1answer
67 views

Setting oblique projection to data visualization

I'm developing a small application using Directx intended to plot frequency spectra data in a waterfall plot. It should look like this: So far, I managed to created most of the chart components(axes,...
2
votes
2answers
372 views

Orthographic Zooming with 0,0 at top/left

I'm trying to implement zooming on my 2D game. Since it's using orthographic projection, I thought it would be easy to implement zooming. After looking around the internet, I found a bunch of ...
2
votes
1answer
253 views

Coordinate spaces and transformation matrices

I'm trying to get an object from object space, into projected space using these intermediate matrices: The first matrix (I) is the one that transforms from object space into inertial space, but since ...
2
votes
4answers
7k views

2D camera perspective projection from 3D coordinates — HOW?

I am developing a camera for a 2D game with a top-down view that has depth. It's almost a 3D camera. Basically, every object has a Z even though it is in 2D, and similarly to parallax layers their ...
2
votes
1answer
2k views

Restoring projection matrix

I am learning to use FBOs and one of the things that I need to do when rendering something onto user defined FBO, I have to setup the projection, modelview and viewport for it. Once I am done ...
2
votes
1answer
140 views

Why does the projection matrix transform object points into a unit cube in computer graphics?

This semester I both took a computer vision and a computer graphics seminar. But only now before the exams I realize that there seems to be a fundamental difference between projection in both topics. ...
2
votes
2answers
233 views

How to calculate a 3D orientation from 2D vanishing lines on an image?

Let say I have a image that represent a 3D scene. I did not have the 3D camera orientation of that scene (left, up and forward vectors) and i'd like to calculate it. On that picture, I draw the ...
2
votes
1answer
204 views

XNA: How do I match Spritebatch View/Projection Matrices with BasicEffect Matrices?

I'm rendering a bunch of 2D content using SpriteBatches to a default XNA viewport. A simple 2D camera is used to move around the scene, which generates a transformation matrix passed to each ...
2
votes
1answer
126 views

Orthogonal projections question

I'm very VERY new into the game development world and I had just some slight trouble wrapping my head around something. We were told between classes just to think about how scaling matrices can ...
2
votes
2answers
386 views

Trying to project a point onto a cubemap

I've got a simple test program with a camera within a cubemap (skybox). You can look around, and it feels like you're in a 3D room, but really it's just a cubemap image. Now I want to draw a point (...
2
votes
1answer
114 views

Minimal Projection Matrix

i hope you can help me. I'm currently stuck at the creation process for projection matrices used by shadow maps. The problem is the following: I got the spot/directional light projectionmatrix/...
2
votes
3answers
484 views

Unproject mouse position to tile — extremely jumpy position?

I'm trying to unproject the mouse position to get the position on the X-Z plane of a ray cast from the mouse. The camera is fully controllable by the user. Right now, the algorithm I'm using is... ...
2
votes
1answer
378 views

Shader issues when creating projection using CreateOrthographicOffCenter instead of CreateOrthographic

Pre. Having these matrix transformations: var scale = Matrix.CreateScale(50f); var eye = new Vector3(0, 0, 10.0f); var view = Matrix.CreateLookAt(eye, Vector3.Zero, Vector3.Up); var projection = ...
2
votes
0answers
27 views

DirectX 11 - Problem with low resolution decals

I'm trying to add a decal system in my DirectX engine but i'm facing some problems with the quality of the textures projected. Every other no decal texture look fine, but these ones look really bad. ...
2
votes
1answer
71 views

How to render multiple projections of an object?

I want to display multiple projection of an object on the same screen. The projection should also change as the body rotates, kind of a dynamic projection of the body. I am trying to make a character ...
2
votes
0answers
169 views

Unproject considering parallax depth

How can I take screen coordinates (or alternatively world coordinates on the 'primary' parallax plane) and find out what world coordinates they translate into when taking parallax depth into account? ...
2
votes
0answers
158 views

Stereo 3D: drawing 2D elements at apparent screen depth

I'm developing an application making use of DirectX11's stereoscopic features. At such I am not relying on nVidia's automatic implementation. That means I have to replicate a way to render 2d elements ...
2
votes
0answers
82 views

uniform z slices in clip-space [closed]

1) Context I'm using a regular OpenGL perspective projection matrix created with GLM (glm::perspective) and taking the inverse (glm::inverse) to transform clip-space back into view space (and world ...
1
vote
2answers
2k views

What dimensions should you use for a perspective projection frustum?

What dimensions should you use for a perspective projection frustum? Initially I created a perspective matrix based on the width and height of the screen, with a calculated zNear value based on a ...
1
vote
3answers
1k views

Orthographic Projection with variable FOV

We are building agame with orthographic view. The problem we face is the fact that with different resolution you can see different area of the game world. E.g. if you have higher resolution you can ...
1
vote
3answers
244 views

Understanding how to go from a scene to what's actually rendered to screen in OpenGL?

I want something that explains step by step how, after setting up a simple scene I can go from that 'world' space, to what's finally rendered on my screen (ie, actually implement something). I need ...
1
vote
1answer
273 views

Simulating flight dynamics in two dimensions

I have decided that in order to improve my math skills and game programming skills I am going to work on a two-dimensional space simulator. The view of the player or camera will be from inside the ...
1
vote
1answer
234 views

How to get UV coordinates for sphere (Cylindrical Projection)

I have created one sphere and I want to map onto it a texture map. But I want first to project my map texture to cylinder and then to sphere. So I want to create a function which takes as ...
1
vote
1answer
1k views

Why are there different ways of building projection matrices?

Matrix.PerspectiveFovLH documentation page says that this method uses the following formula to build a perspective projection matrix. [w, 0, 0, 0] [0, h, 0, 0] [0, 0, zFar/(zFar - zNear), 1] [0, 0, -...
1
vote
1answer
649 views

Trouble with SAT style vector projection in C#/XNA

Simply put I'm having a hard time working out how to work with XNA's Vector2 types while maintaining spatial considerations. I'm working with separating axis theorem and trying to project vectors onto ...
1
vote
1answer
63 views

Does projection take place before clipping in the rendering pipeline?

At first I thought clipping happens before projection since new vertices may be added and the output of projection is in NDC which is 2D. However after a lot of googling, I found that some articles/...
1
vote
1answer
82 views

Rendering order for units behind objects?

Im developing a 2D game with some fake 3D effects (parallell projection). 2D-units are able to walk in front of buildings aswell as behind them, although themselves being just 2d-objects. This leads ...
1
vote
1answer
289 views

Where is the error in my perspective projection implementation?

My question is not really a game development question, but since it's based on 3D programming, I thought it would fit best here. I've got a line made out of Point3D objects where the value of x, y, ...
1
vote
1answer
179 views

Why does everything appear backwards when using orthographic projection?

I may not be calculating my orthographic projection matrix properly. What can I do to ensure that my scene renders correctly when using orthographic projection? The rendering order appears to be ...
1
vote
1answer
770 views

Project location to perspective fake 3D view

I am trying to implement a perspective view in a 2D soccer game, such like Nintendo World Cup. In this case, the soccer pitch will look like a isosceles trapezoid, but not a rectangle in real. Here ...
1
vote
2answers
304 views

projected textures not appear on the “back” of the mesh as well?

I want to create blood wounds on my character's bodies by using projected textures. I've watched some commentaries on games like Left 4 Dead and they say they use projected textures for the blood. But ...
1
vote
1answer
308 views

Drawing Projected Vertices/Faces In Order

I recently created a 3d engine, and have gotten to what is (as I've found) the hardest part so far. I need to sort the objects and then draw them. I've looked at sorting algorithms, but my case is ...
1
vote
1answer
26 views

How do I take 2D ballistic trajectory planning and apply it to 3D?

I am currently using this formula speed = sqrt((gravity.y*target.x^2)/(2*cos^2(angle)*(target.y - target.x*tan(angle))) provided by DMGregory as an answer for my question here to determine the ...
1
vote
1answer
51 views

seamless stereographic projection

i have been struggling with this problem on and off for a few years now - making a seamless stereographic projection texture mapping on a sphere where the two halves of the sphere use the projection ...
1
vote
2answers
631 views

How to determine the visibility of a single vertex, given a viewpoint?

I have a 3D triangle mesh, and I want to know, given a viewpoint (defined by a model, view and projection matrix), if a certain vertex is visible or not. My approach was to render the mesh using ...
1
vote
1answer
184 views

projection / view matrix: the object is bigger than it should and depth does not affect vertices [closed]

I'm currently trying to write a C 3D software rendering engine from scratch just for fun and to have an insight on what OpenGL does behind the scene and what 90's programmers had to do on DOS. I have ...
1
vote
3answers
646 views

OpenGL ES, orthographic projection and viewport

I want to make some simple 2D game on iOS to familiarize myself with OpenGL ES. I started with Ray Wenderlich’s tutorial (How To Create A Simple 2D iPhone Game with OpenGL ES 2.0 and GLKit). That ...
1
vote
1answer
167 views

Orthogonal projection and world transform

I'm reading about projection matrix. Needs of perspective projection is obvious, but I'm not sure about orthogonal projection. Because orthogonal projection effect looks possible with only world ...
1
vote
2answers
1k views

How would I achieve diablo like 2D isometric projection?

I am in the process of coming up with an idea for a game, and I would like it to be isometric like Diablo. The problem is I have no idea how it achieves the effect of height like in the following ...